1. Field of the Invention
The present invention relates to a record retrieval method, a record extraction method, and a record extraction apparatus and, more particularly, to a record retrieval method, a record extraction method, and a record extraction apparatus for retrieving a record meeting designated conditions from a plurality of records in a data processor.
2. Description of the Related Art
In conventional data retrieval processing used in computer systems and the like, a general method of designating a retrieval condition on which records stored in, e.g., a large-capacity external storage device and consisting of a plurality of fields are retrieved is to directly input (including selection of a list using a sub-window) a code as the key of the retrieval condition or to directly input a condition (range) with respect to a specific item on a file.
In this retrieval condition input method used in the conventional data retrieval processing, however, a code serving as the key of a retrieval condition is directly input (including selection of a list using a sub-window) or a condition (range) with respect to a specific item on a file is directly input. Accordingly, the method has the following problems.
That is, to retrieve a file under a certain condition in the above retrieval condition input method, it is necessary to predetermine the retrieval condition or to know the key code meeting the retrieval condition in advance. To find the range of the retrieval condition and obtain the key code within the range by using a method of trend analysis, it is necessary to recognize the overall trend, determine the range of the condition to be obtained, retrieve a file within the range of the condition, confirm the retrieval result, and obtain an appropriate key code by trial and error. Since a number of these processing steps are necessary, the procedure is cumbersome and time-consuming. Additionally, discontinuity of the work results in a low work efficiency.
Also, in conventional database systems used in enterprises and the like, various records are stored in a database and the data amount is huge. Accordingly, to extract necessary records from the database, it is necessary to ask an operator having expert knowledge on the database or to perform troublesome operations at a system terminal managing the database. That is, in such an operation environment, not all users can readily perform extraction of records, and this lowers the availability of the database.